d3d12/wgl/test: Fixes wgl_tests.cpp for d3d12 with mingw

wgl needs dxguids/dxguids.h for correct GUID

Signed-off-by: Yonggang Luo <luoyonggang@gmail.com>
Reviewed-by: Jesse Natalie <jenatali@microsoft.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16767>

src/gallium/targets/libgl-gdi/tests/wgl_tests.cpp

@@ -145,6 +145,7 @@ TEST(wgl, basic_create)
  * the environment isn't set up to run them.
  */
 #include <directx/d3d12.h>
+#include <dxguids/dxguids.h>
 #include <wrl/client.h>
 #include <memory>
 using Microsoft::WRL::ComPtr;